Battery Basics

Get a charge out of knowing more

By Athena Ransom

Batteries are the heart of your motorcycles electrical system and require care and maintenance regularly. Here are some basic questions and answers regarding a motorcycle battery.

1. How often do I get a new battery?
There is no set time limit on how long a battery lasts. I can get anywhere from three to five years on my factory battery. I ride long distances (more than 20 miles) four to six to days a week all throughout the year. By doing so, the current flow created within the charging system of my bike keeps the battery charged. When a bike is not ridden daily the charge will diminish with starting and short/brief stints of riding. A trickle charger (otherwise known by the brand name “battery tender”) offers some assistance for maintaining the life of the battery, but no life expectancy can be assured with any battery.

A sealed battery (maintanence free) taken out of the motorcycle for the winter and hooked up to a trickle charger.

Factory recommended batteries will provide the most battery life possible with proper maintenance. Newer style “gel/sealed” batteries, otherwise known as maintenance free, require very little, if any, maintenance with the exception of winter storage (i.e. maintaining a charge with a battery trickle charger during down time). Older style “water” batteries require a fluid/acid level check quarterly during riding season. They also require certain storage requirements during winter storage, information that can be found in your motorcycle service manual.

A conventional battery (left) has six filler caps on top, a vent hose on the left, and lines on the front indicating the upper and lower levels for battery acid. The maintenance-free battery (right) has none of these things.

2. What is a trickle charger and how do I use one?
A trickle charger is a charging device that charges a battery and then can stay attached to the battery to maintain the charge. Charging goes into storage mode. A trickle charger is different than a battery charger. A charger needs to be removed when the battery is charged or you run the risk overcharging the battery.

A trickle charger from Deltran called a battery tender. When it is charging mode, the red light is on. When it reaches storage mode, the green light illuminates.

Its recommended that people who dont ride their motorcycles on a regular basis attach a trickle charger to the battery during the down time. When youre ready to ride, detach it from the battery. In an ideal situation, the battery is fully charged and the motorcycle should start right up.

A battery tender from Deltran that can charge up to four different batteries at a time.

3. How do I check if my battery is running out of juice?
There are two tests you can run using the proper tools. The first is a surface test and this requires a voltmeter. While the bike is turned off, place the voltmeter on DC volts and place the probes pole to pole (negative to negative, positive to positive) on your battery. A good battery will show 12.65 volts on the meter or better. Note: if you have a Lucas Charging System (positive ground charging system) present on older British bikes like Triumph and BSAs, the process would be reversed. A voltmeter is a good tool to own if you have a motorcycle. It can purchased for around $25 at any electronics store or motorcycle accessories outlet.

A voltmeter shows a volt reading for this conventional “water” battery.

A surface test provides a basic idea of your batterys output. To obtain all information on your battery a “load test” is required. A load test reveals the condition of the battery and its charging system, basically, the batterys ability to perform correctly. This test is done with a battery load tester tool, which sells for about $30 to $40. Most motorcycle shops have this tool and will perform this test on site or you can purchase it at most auto parts stores. Make sure to purchase a battery load tester specific for motorcycles. Refer to the tool instruction manual for proper hook up and testing procedure. A good battery will take a 10 second load at 10.5 volts or better.

4. How do I tell if the battery is dead?
When there is no voltmeter or load tester available, put the bike in neutral, turn on the lights and push the starter button. If the lights dim and the bike will not start you have a dead battery. If the lights do not dim when pushing the start button and the bike will not start, you have a starting problem.

A battery being charged while it#39;s in the motorcycle.

5. What causes my battery to go dead?
Many things can cause a battery to die and no exact reason applies to each rider. I have found most batteries die due to age and lack of constant current flow through the charging system.

As I mentioned previously, when a bike is not ridden daily the charge will diminish with starting, and short or brief stints of riding. Also, accessories have an impact on your charging system. Motorcycle charging systems and battery sizes are designed around the electrical requirements of the bike as it comes from the factory. Extras such as accessory lighting, radios and other add-ons can cut down on the life of your battery and charging system. These accessories require more amperage draw from your battery. Together with your accessories and factory requirements the total current draw is more than the battery can put out. As well, a charging system problem can also cause your battery to be drained and go dead. A charging system test can be performed as explained in the next question and answer.

Two sealed batteries hooked up to a multi-port Deltran Battery Tender, part of winter storage maintenance.

6. What do I do if I have a dead battery?
Locate where the battery is by consulting your motorcycle owners manual. Remove the negative cable first and then the positive cable from the battery. Remove the battery as indicated in your manual, and then replace it with the factory recommended battery. Be aware that you must first charge the new battery with a motorcycle battery charger to the fullest possible charge. A battery has a memory and must start with the highest amount of voltage to be able to maintain the highest amount of voltage within its life span. Ask your dealer if the battery youÍre buying is charged. Most are not. See if your dealer can charge it for you before taking it home. Not everyone owns a motorcycle battery charger, although its a good product to own if you have a motorcycle. As explained above, a charger is different from a trickle charger. A battery charger must be removed when the battery is fully charged where a trickle charger can stay attached to the battery to maintain the charge, for example, during winter storage.

Place the charged battery in the bike and attach the cables, positive first and negative second.(Again, if you have an antique/older British bike with a Lucas Charging System, the process would be reversed as these bikes have a positive ground system.) Once the battery has been re-installed the charging system must be checked to insure the battery will not be drained by any charging system issues.

The charging system test is very simple and can be done with the voltmeter. Place the voltmeter on DC Volts and place leads pole to pole negative to negative, positive to positive). Start the bike, allow for warm-up time — at least 30 to 90 seconds — and watch as the volts reading go up. At this time, rev the bike 1000 to 1500 rpm and watch the volt reading on the meter go up again. Make note of the reading and then refer to your motorcycle manufacturers specification for the charging system output. Compare the readings to determine if your motorcycle charging system is operating properly. Note: Do not over-rev your motorcycle during this test. If your readings do not fall within your manufacturers specifications, further diagnostic testing is required.

7. Can I jumpstart my bike with a car?
Yes, but only with the car turned off, i.e. not running. Motorcycle electrical systems work with a lower amperage then cars. Cars put out approximately 200 amps when running and motorcycles only put 32 to 40 amps when running. If you attempt to jump start your bike with a car that is running you could cause the battery to blow up, which can result in damage to your motorcycle and/or physical injury. I carry motorcycle jumper cables for when my friends’ bikes have battery issues. You can jumpstart one motorcycle from another and the motorcycle can be running.

Helpful Web Sites

Battery Chargers

Motorcycle Battery Manufacturers

Athena Ransom owns her own motorcycle shop, Vagabond Chopper Company, in Pompano Beach, Florida, where she repairs and builds custom motorcycles. Her bikes have been featured in numerous motorcycle magazines and bike shows. She has been riding and wrenching on motorcycles since 1994 and is married with two children.

If you have questions, feel free to call my shop, Vagabond Chopper Company, at 954.360.0075, or email You can also post a comment or question below and I will respond so all can benefit from my answer.

7 thoughts on Battery Basics

  1. Your info on the bike batteries was great. Having trouble with my girlfriend's bike starting. I have the same bike but mine is fine; they were bought the same time brand new three years ago. Not a Harley. Honda Rebels — starting small then growing up in a few years.

  2. This is a very informative article for me. I bought a Harley Super Glide the day after Thanksgiving (2008) and have only gotten to ride it five (short) times due to weather. I have started to wonder what I needed to do for the battery if it stayed unridden for a while.

  3. Newbie rider. Took the course. Just got my license. Excited to learn more. Thinking about moving up from a Honda Rebel to HD Sportster or Honda Shadow. Hmm, don't know which. I hear Harleys require more maintenance. Any truth to that?

  4. I'm not riding my own bike yet, but I'm looking forward to my first purchase and the information I receive from your Web site sure makes me feel like a well informed rider. Thanks!

  5. Hey Gen,
    You are “right on” again, girlfriend. The article on batteries was great and very, very informative. You always give such specific and good advice to female riders. And you always break everything down in layman's terms. Even though I know how to maintain my bike, the rest of the information was great – the advice about checking the charge on the battery. Many thanks to a great job.

    1. You are very welcome. Eydie is referring to the E-Newsletter that we send out every week. This week's promoted this battery story. I wrote how maintaining one's battery is one of the easiest things to know about your bike. Sign up to receive the e-newsletter by clicking on the link on the left under Extras. It promotes the latest stories posted and gives a Riding Tip of the Week.

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